Field of the Invention and Related Art
The present invention relates to a cartridge, and an electrophotographic image forming apparatus employing a cartridge.
Here, an electrophotographic image forming apparatus is an apparatus for forming an image on a recording medium (for example, a recording paper, an OHP sheet, and the like) with the use of an electrophotographic image forming method. It includes an electrophotographic copying machine, an electrophotographic printer (a laser printer, an LED printer, and the like), a facsimile apparatus, a word processor, and the like.
A cartridge system has long been in use, according to which a developing member and a developer storage portion, for example, are integrated in the form of a cartridge which can be removably mountable in the main assembly of an image forming apparatus. Also according to a cartridge system, a developing member as a processing means can be easily maintained by a user him/herself, remarkably improving the operability of an image forming apparatus. Therefore, a cartridge system is widely used in the field of an electrophotographic image forming apparatus.
An electrophotographic color image forming apparatus employs a rotary device, which is disposed within the apparatus main assembly. Further, a structural arrangement has been known, which makes it possible to removably mount four development cartridges, in which four developers, different in color, are stored one for one, in this rotary device.
In the past, the following structural arrangement was devised to prevent a development cartridge from becoming dislodged from the rotary device when the rotary device is rotated.
For example, the end plates of the development cartridge are each provided with a projection, and the development cartridges are inserted into the apparatus main assembly so that these projections move along the corresponding guides on the rotary device side. Further, the end portion of each guide is provided with a spring enabled to catch the projection, so that the cartridge is held to the rotary device by the force generated by the resiliency of the spring. In the case of this structural arrangement, however, in order to ensure that a cartridge does not become dislodged from the rotary device due to the centrifugal force generated as the rotary device is rotated, the force generated by the resiliency of the spring must be substantial; in other words, the spring must be stiff enough to generate such a force. Providing the end portion of the guide with a spring stiff enough to generate such a force increases the load generated when a cartridge is mounted into, or dismounted from, the rotary device. Further, when mounting or dismounting a cartridge, the left and right springs are likely to become disengaged non-simultaneously from the cartridge, making it possible that the cartridge will become tilted and hang up in the rotary device. On the other hand, reducing the stiffness of the spring to reduce the cartridge retaining force of the spring makes it possible for a cartridge to fall out of the rotary device and damage the apparatus main assembly. Thus, the spring must be made neither too stiff nor too soft so that a proper amount of force is generated by the resiliency of the spring.
The primary object of the present invention is to provide a combination of a cartridge and an electrophotographic image forming apparatus, in which the cartridge can be more efficiently mounted into, or dismounted from, the main assembly of an image forming apparatus.
Another object of the present invention is to provide a combination of a cartridge and an electrophotographic image forming apparatus, in which the cartridge does not become unexpectedly dislodged from the main assembly of an image forming apparatus after the mounting of the cartridge into the apparatus main assembly.
Another object of the present invention is to provide a combination of a cartridge and an electrophotographic image forming apparatus, which ensures that the cartridge is placed in a predetermined position in the main assembly of an image forming apparatus as the cartridge is mounted into the image forming apparatus main assembly, and that cartridge remains in the predetermined position after the mounting.
Another object of the present invention is to provide a combination of a cartridge and an electrophotographic image forming apparatus, in which the cartridge does not become unexpectedly dislodged from a rotary device as the rotary device is rotated after the mounting of the cartridge into the rotary device, that is, a part of the image forming apparatus main assembly.
Another object of the present invention is to provide a combination of a cartridge and an electrophotographic image forming apparatus, in which as an operator releases his or her hand from the handgrip of the cartridge, which has been grasped by the operator in order to mount the cartridge into the main assembly of the image forming apparatus, the cartridge locking portion of the cartridge engages the cartridge locking portion of the main assembly of the image forming apparatus.
Another object of the present invention is to provide a combination of a cartridge and an electrophotographic image forming apparatus, in which as an operator grasps the handgrip of the cartridge in order to dismount the cartridge from the main assembly of the image forming apparatus, the cartridge locking portion of the cartridge disengages from the cartridge locking portion of the main assembly of the image forming apparatus.
Another object of the present invention is to provide a combination of a cartridge and an electrophotographic image forming apparatus, in which the mounting or dismounting of the cartridge is instinctively understandable to an operator, and the cartridge is smoothly mountable into, or dismountable from, the main assembly of the image forming apparatus.
These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.